Response to thermal stimulus
Film 30 Disturbances in the circumnutation trajectory induced by thermal stimulation of a leaf whose axis was perpendicular to the longitudinal axis of circumnutation. Yellow line - circumnutation trajectory prior to application of a thermal stimulus; red line - circumnutation trajectory after application of a thermal stimulus.
Application of the thermal stimulus (30-s burning of the leaf tip) evokes a variation potential (VP) in the sunflower stem, which is transmitted down the stem
The red line represents a ca. 100 mV VP recorded under the stimulated leaf; the black line shows a low-amplitude VP recorded on the opposite side of the stem in the motor zone.
The transmission of such an asymmetric ca. 1-h depolarisation wave along the stem causes characteristic circumnutation disorders dependent on the position of the stimulated leaf on the stem and the circumnutation phase in which the stimulus was applied.
Film 31 Disorders in the trajectory leading to changes in the circumnutation direction. Thermal stimulation was applied to a leaf with a parallel axis to the longitudinal axis of circumnutation.
Stolarz M, Dziubińska H, Krupa M, Buda A, Trębacz K, Zawadzki T (2003)
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